1. Field of the Invention
The present invention relates to an electroacoustic transducer provided with a mechanical impedance transformer, capable of emitting powerful acoustic waves in a liquid environment.
2. Description of the Prior Art
French Patent applications FR-A-2,667,518 and 2,678,390 describe electrohydraulic vibrating sources suited for working notably in wells where the vibrations generated by a piling of piezoelectric disks are applied to pads coupled with an underground formation by means of hydraulic jacks and connecting circuits. Selection of the sections of the jacks allows the obtaining of a mechanical amplitude impedance matching and an amplification of the amplitude of the vibrations applied to the ground by the pads.
U.S. Pat No.5,069,308 describes a source of acoustic waves suited for working in a well, which comprises a tubular body, an electromechanical generator consisting of one or two pilings of piezoelectric disks, coupled with a mechanical impedance transformer which lowers the acoustic impedance of the generator. The transformer comprises several flexible elongated blades arranged symmetrically around the central axis of the body. The central part of each blade has an elliptical curvature in a radial plane and it is connected at its opposite ends to two plates substantially perpendicular to the axis of the source, which rest on vibrating faces of the generator.